"It has been a good project for us," says Spagat, who has also done mill-to-office conversions in such Bay State communities as Clinton, Newton and North Andover. Brickstone Square has attracted a mix of professional services, high-tech and institutional companies since opening in 1988. CMGI, one of the country's leading venture capital firms, occupies more than 400,000 sf in the complex.

"Brickstone Square provides an attractive investment opportunity because of its exceptional location, first-class amenities and accessibility to a skilled labor force," says Sonnenblick-Goldman President Steve Kohn, whose firm has been retained to market the property. Kohn notes that the North suburban office region has been among the strongest around of late. Meredith & Grew places the current vacancy rate for the 20.3 million-sf market at 4.9% following year-to-date absorption of 808,000 sf.

Along with its proximity to both Route 495 and Interstate 93, Spagat says Brickstone Square meets all the physical requirements needed to make a successful mill rehab, including high ceilings, extensive window lines and 60,000-sf floorplates. "People love the space," he says. A native of Chicago, Spagat came to Massachusetts in 1980 to concentrate on mill conversions, although his firm has branched out in recent years to develop new buildings as well.